1. Field of the Invention
The present invention relates to gain adjustment for a wireless communication circuit, and more particularly, to a gain adjustment device for a wireless communication circuit using linearity of power of a reception signal and related gain adjustment method thereof.
2. Description of the Prior Art
In general, for a radio frequency (RF) integrated circuit (IC), the gain of the RF IC should be fixed once being manufactured. However, the differences (e.g., different lengths of traces, variations of permittivity, etc.) between the printed circuit boards, temperature variations, different production batches, or different environments in which the RF IC is used are all likely to cause the gain of the RF IC to shift. The gain shift of the RF IC will worsen linearity of a power amplifier, making I/Q-mismatch at the transmitter end more complicated, and therefore affecting the performance of calibration at the receiver end.
Thus, there is a need to provide a method and device to automatically locate the gain shift and a corresponding adjustment parameter, to ensure the linearity of the transmitter, such that the RF front-end may yield a proper signal to noises ratio (SNR) to thereby mitigate transmission quality deterioration caused by an I/Q-mismatched environment.